US20100159344A1 - Fuel cell seals - Google Patents
Fuel cell seals Download PDFInfo
- Publication number
- US20100159344A1 US20100159344A1 US12/591,986 US59198609A US2010159344A1 US 20100159344 A1 US20100159344 A1 US 20100159344A1 US 59198609 A US59198609 A US 59198609A US 2010159344 A1 US2010159344 A1 US 2010159344A1
- Authority
- US
- United States
- Prior art keywords
- seal
- fuel
- fuel cell
- seal member
- cell stack
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
- H01M8/0276—Sealing means characterised by their form
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
- H01M8/028—Sealing means characterised by their material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
- H01M8/028—Sealing means characterised by their material
- H01M8/0282—Inorganic material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
- H01M8/0286—Processes for forming seals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/2465—Details of groupings of fuel cells
- H01M8/2483—Details of groupings of fuel cells characterised by internal manifolds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
- H01M2008/1293—Fuel cells with solid oxide electrolytes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- the present invention is generally directed to fuel cell components and more specifically to multiple member protected anode fuel cell seals.
- Fuel cells are electrochemical devices which can convert energy stored in fuels to electrical energy with high efficiencies.
- High temperature fuel cells include solid oxide and molten carbonate fuel cells. These fuel cells may operate using hydrogen and/or hydrocarbon fuels.
- an oxidizing flow is passed through the cathode side of the fuel cell while a reducing flow is passed through the anode side of the fuel cell.
- the oxidizing flow is typically air
- the reducing flow typically comprises a mixture of a hydrogen-rich gas created by reforming a hydrocarbon fuel source and water vapor.
- the fuel cell typically operating at a temperature between 750° C. and 950° C., enables the transport of negatively charged oxygen ions from the cathode flow stream to the anode flow stream, where the ions combine with either free hydrogen or hydrogen in a hydrocarbon molecule to form water vapor and/or with carbon monoxide to form carbon dioxide.
- the excess electrons from the negatively charged ions are routed back to the cathode side of the fuel cell through an electrical circuit completed between anode and cathode, resulting in an electrical current flow through the circuit.
- Fuel cell stacks are frequently built from a multiplicity of cells in the form of planar elements, tubes, or other geometries. Fuel cell stacks, particularly those with planar geometry, often use seals between electrolyte and interconnect surfaces to contain fuel and air at various locations within the stack. While it is desirable for seals to be effective at start up temperatures to prevent escape (and potential ignition) of fuel gasses, these seals must maintain their operating integrity at high operating temperatures and in an oxidizing, reducing, or mixed (i.e., oxidizing on one side on one side of the seal and reducing on the other) environment. Expansion and contraction of fuel cell stack components (including seals) due to thermal cycling or compression should not result in damage to any of the components during a seal's expected life.
- brazes and metal gaskets Many types of seals used at elevated temperatures, such as brazes and metal gaskets, often have a limited life, tolerating only a relatively few number of thermal cycles before they fail to maintain a hermetic seal due to differences in the coefficients of thermal expansion (CTE) that result in mechanical stresses that can lead to failure of the seal or the components of the assembly.
- CTE coefficients of thermal expansion
- Some assemblies are difficult to seal with brazes or gaskets because of operating conditions or material incompatibilities.
- brazes and metal gaskets often present difficulties and high costs of fabrication and assembly due to the tighter tolerances which are required, in flatness for example, to ensure formation of a hermetic seal.
- An embodiment of a first aspect of the present invention provides a method of sealing a fuel cell stack comprising forming a seal with a metal seal member and one or more additional seal members; wherein said metal seal member is exposed to a reducing environment in the interior of the fuel cell system.
- An embodiment of the second aspect of the invention includes a method of operating a fuel cell stack, said method comprising providing fuel into a fuel cell stack, providing air into a fuel cell stack, allowing fuel to permeate through a secondary seal from at least one fuel channel in a first interconnect into a chamber located in the fuel cell stack between a primary and the secondary seals, and allowing air to flow into the chamber from an air channel in a second interconnect through an opening in the electrolyte to form a protective environment in the chamber for the primary seal.
- An embodiment of the third aspect of the invention includes fuel cell stack comprising a plurality of fuel cells, a plurality of interconnects, one or more first seal members comprising a first seal material which are located within the fuel cell stack in fuel flow areas, and one or more second seal members comprising a second seal material different from the first seal material which are located within the fuel cell stack in air flow areas.
- the one or more first seal members are more chemically stable in a reducing environment than the one or more second seal members, and the one or more second seal members are better coefficient of thermal expansion (CTE) matched to the fuel cells and interconnects than the one or more first seal members.
- CTE coefficient of thermal expansion
- FIG. 1A is a top view of an exemplary interconnect from a SOFC with a multiple member donut barrier seal.
- FIG. 1B is a close up view of an exemplary multiple member donut bather seal.
- FIG. 2 is a three dimensional view of an exemplary interconnect from a SOFC with a multiple member window barrier seal.
- FIG. 3 is a top view of a exemplary donut seal where a gap is defined between two seal members.
- FIG. 4 is a top view of a second exemplary donut seal where two seal members abut.
- FIG. 5 is a side cross sectional view of repeating elements in an exemplary SOFC stack employing a multiple member seal of the third and fourth aspects of the present invention.
- forming an effective seal does not require the formation of a perfectly hermetic seal. Rather, forming an effective seal indicates that a seal member is defining the boundary of a pressure differential or is forming a physical deterrent to substantial gas flow from one side of the seal to the other.
- a “semipermeable seal” is an effective seal in that it allows it allows some transfer of gas flow from one side of the seal to the other while maintaining a physical deterrent to substantial gas flow across the seal.
- a “hermetic seal” is a seal that prevents substantially all gas movement across the boundary defined by the seal. Such seals may be referred to herein as impermeable seals.
- the terms “inside” or “inner” describe the position of one seal member relative to another in a multiple member seal where the inside or inner seal member is at a position closer to the interior of the sealed area. Conversely, the outer or outside member is at a position closer to the outside of the sealed area.
- typical SOFC operating temperature includes a temperature that falls within the range of 750° C. to 950° C., inclusive.
- a seal member's thickness is the distance between two elements in contact with the seal member.
- the two elements may be two planar stack elements that form a top and bottom of the seal member.
- a seal member's width is the distance from the inside of the sealed area to the outside of the sealed area.
- a seal in a “mixed environment” has a reducing environment on one side of the seal and an oxidizing environment on the other.
- the reducing environment is the fuel/water mixture within the fuel cell system and the oxidizing environment is either the outside of the fuel cell system or a portion of the oxidizing flow within the fuel cell system.
- Certain glass and glass ceramic compounds have been shown to be able to provide robust high temperature seals and have coefficients of thermal expansion (CTE) that are well matched with the those of electrolytes and interconnects used in typical SOFCs. This CTE matching is important to minimize mechanical stresses that would otherwise lead to cell cracking and delamination during thermal cycling.
- CTE-matched glass and glass ceramic seals typically have a shortcoming in that their effectiveness diminishes with prolonged operation in a high temperature reducing environment, such as the fuel/water mixture in a SOFC. It is therefore desirable to have a method of sealing a fuel cell system with a CTE-matched glass or glass ceramic high temperature seal, yet reducing contact of chemically vulnerable glass or glass ceramic seals and the high temperature reducing environment of the SOFC.
- seal materials useful in the present invention that are not chemically vulnerable to reducing environments at typical SOFC operating temperatures need not be able to form and maintain hermetic seals at these temperatures.
- seal materials useful in the present invention that are capable of forming and maintaining hermetic seals at typical SOFC operating temperatures need not be chemically invulnerable to reducing environments at the same temperatures.
- Seals useful in all aspects of the present invention can be constructed in any geometric shape necessary for their application.
- a SOFC stack may contain multiple fuel cells, manifolds for fuel and/or air, and various internal interconnects. At the junction of each of these components, a distinctively shaped seal may be required to maintain an effective seal at typical operating temperatures.
- Exemplary geometric shapes include rings (i.e., donuts), strips (both shown in FIG. 1 ), or rectangles (i.e., windows) (shown in FIG. 2 ) or any combination thereof.
- Multiple member seals of the present invention will be particularly useful at any junction where the seal is presenting a barrier to the reducing environment, i.e. the fuel/water flow, such as hydrogen or hydrocarbon fuel (including methane, natural gas, etc.) and water vapor, of the fuel cell system.
- Other seal shapes may be used for other configurations.
- FIG. 1A shows the air side of an exemplary interconnect 1 .
- the interconnect may be used in a stack which is internally manifolded for fuel and externally manifolded for air.
- the interconnect contains air flow grooves 2 to allow air to flow from one side 3 to the opposite side 4 of the interconnect.
- Ring seals 5 are located around fuel manifold riser openings 6 .
- Strip seals (not shown) are located on lateral sides of the interconnect 1 .
- FIG. 1B shows a close up view of an exemplary seal 5 .
- Seals 5 and lateral strip seals contain a metal seal member 8 which faces the fuel/water flow areas and a glass or glass ceramic seal member 9 which faces the air flow areas.
- member 8 is the inner seal member and member 9 is the outer seal member.
- member 8 In lateral seals of air sides of interconnects, member 8 would be the outer seal member and member 9 would be the inner seal member.
- FIG. 2 illustrates the fuel side of the interconnect 1 .
- a window seal 10 is located on the periphery of the interconnect 1 .
- Seal 10 contains the metal seal member 8 as the inner seal member and the glass or glass ceramic seal member 9 as the outer seal member. Also shown are fuel distribution plenums 11 and fuel flow grooves 12 .
- the fuel side of an interconnect may have fuel flow grooves 12 that are all the same depth and length, or a combination of short and long, and/or deep and shallow grooves.
- the air side of the interconnect 1 contacts a cathode of one cell in the stack while the fuel side of interconnect 1 contacts an anode of the adjacent cell.
- Multiple member seals of the first aspect of the present invention comprise a metal seal member and one or more additional seal members.
- a metal seal member of a multiple member seal is positioned to lie between a more chemically vulnerable seal member, such as a glass or glass ceramic seal member, and a reducing environment (such as a fuel/water flow) within a fuel cell.
- a metal seal member may be processed into any suitable form; for example foil, wire, or felt.
- the metal used for a metal seal member comprises gold, silver, nickel, tin, or any alloy thereof.
- At least one of the one or more additional seal members comprise glass or glass ceramic.
- Glass or glass ceramic seal members can be processed in any suitable process, such as dispensing, tape casting and tape punching. Such processes are numerous and well known in the art. Examples of materials for glass or glass ceramic second seal members include higher temperature modified borosilicate glasses with a high content of BaO and Al 2 O 3 and lower temperature pure borosilicate glasses, although any other glass or glass ceramic material with a suitable viscosity profile can be used.
- the metal seal member facing a fuel/water flow forms a protective barrier against fuel/water exposure for the second glass or glass ceramic seal member.
- Formation of a perfect hermetic seal by the metal first seal member is not necessary to provide a protective barrier; merely forming an effective seal is sufficient to keep the bulk of the reducing environment from contacting the more vulnerable glass or glass ceramic seal member.
- the closer the seal formed by the metal seal member is to being hermetic the more effective the protective barrier will be, thus allowing for a longer effective lifespan of the glass or glass ceramic seal member.
- any two seal members can be positioned such that they are in contact (i.e., abut) or positioned such that a gap is defined between them.
- FIG. 3 An illustration of an exemplary concentric ring seal where a gap is defined between two seal members is found in FIG. 3 . As seen in this figure, a gap 13 is located between an outer seal member 9 and an inner seal member 8 .
- FIG. 4 An illustration of an exemplary concentric ring seal with abutting seal members is found in FIG. 4 . As seen in this figure, contact at position 14 occurs between an outer seal member 9 and an inner seal member 8 .
- Multiple member seals useful in the second aspect of the present invention comprise one or more secondary seal members comprising a material that is chemically stable in a mixed environment (i.e., reducing flow, such as a fuel/water flow, on one side of the seal member and oxidizing flow, such as air, on the other) and one or more primary seal members. Further, a gap is defined between the secondary seal member and the primary seal member such that at least one channel is defined through which a protective oxidizing flow is flowed.
- the one or more secondary seal members are located in the fuel cell stack such that the fuel/water is on one side of the seal member and the one or more secondary seal members need only form an effective, but not hermetic, seal.
- Materials useful in constructing primary and secondary seal members may be processed in any suitable process, such as dispensing, tape casting and tape punching. Such processes are numerous and well known in the art.
- Embodiments of seals according to the second aspect of the present invention utilize one or more primary seal members to effectively isolate areas of the fuel cell stack from either the outside atmosphere or areas of air flow within the fuel cell stack and one or more secondary seal members prevent reducing flow inside of the fuel cell system from contacting and degrading the primary seal members.
- at least one of the one or more primary seal members comprises a glass or glass ceramic seal member.
- the secondary seal members comprise a material capable of forming merely an effective seal at typical SOFC operating temperatures.
- the material of the second seal members also must be relatively chemically invulnerable to the reducing atmosphere.
- a secondary seal member may comprise a metal or metallic felt.
- the metal or metallic felt used for a secondary seal member will comprise gold, silver, nickel, tin, or any alloy thereof.
- Examples of materials envisioned for use in preferred glass or glass ceramic primary seal members include higher temperature modified borosilicate glasses with a high content of BaO and Al 2 O 3 and lower temperature pure borosilicate glasses, although any other glass or glass ceramic material with a suitable viscosity profile can be used.
- SOFC components are adapted to allow for an oxidizing flow to enter a channel defined between the outermost secondary seal member and the innermost primary seal member at a pressure lower than the pressure of the reducing flow.
- the secondary seal members need not form a hermetic seal; a small amount of leakage of the reducing environment into the channel between the seal members is acceptable. Due to the differences in the pressures of the reducing flow and oxidizing flows found on either side of the secondary seal, any leakage across the seal will be in the form of the reducing flow entering the oxidizing flow in the channel.
- the oxidizing flow in the channel will act as a protective buffer in that any reducing environment that escapes containment will contact the protective oxidizing flow in the channel and be neutralized before it can contact the outermost primary seal member.
- the one or more primary seal members need not be chemically invulnerable to a reducing atmosphere.
- the primary seal members do, however, need to be able to hermetically form and maintain a seal at typical SOFC operating temperatures.
- the one or more primary seal members hermetically seal the fuel cell system at these temperatures.
- the SOFC components can be adapted in a number of ways to allow for the low pressure oxidizing gas flow to flow through the chamber described above.
- the SOFC system is a planar stack system utilizing planar electrolytes and interconnects.
- the planar electrolytes for electrolyte supported cells
- the holes may be formed in the electrodes.
- FIG. 5 shows a portion of an exemplary SOFC stack including repeating planar interconnects 1 and fuel cells 20 utilizing seals according to the second aspect of the present invention.
- Each fuel cell 20 includes an electrolyte 21 , anode electrode 22 , and cathode electrode 23 .
- This illustration is not meant to be limiting because, as stated above, embodiments of seals useful in the present invention may be fabricated in any geometric shape necessary to contain the reducing flow.
- Respective air and fuel flow grooves and channels 2 and 12 in interconnect 1 are defined between each respective electrode 22 , 23 and the interconnects that lie above and below the electrodes.
- the reducing flow e.g., fuel and water
- the oxidizing flow e.g., air
- Opening 34 in the interconnect is indicated in FIG. 5 by dashed lines. Note that any combination of openings 24 and openings 34 may be utilized in various embodiments of the present invention to provide air flow to chambers 25 in a fuel cell stack. For example, in some embodiments, only opening 24 in the electrolyte is present. In other embodiments, only openings 34 in the interconnects are present. In still other embodiments, both openings 24 and 34 are present.
- At least two compositionally distinct glass or glass ceramic seal members are used to reduce the contact of the reducing environment in an SOFC system and more chemically vulnerable glass or glass ceramic seal members.
- the first type of seal member is preferentially composed of a glass or glass ceramic that is more chemically stable in a reducing environment than the second type of seal member.
- the second type of seal member is preferentially composed of a glass or glass ceramic that has a coefficient of thermal expansion (CTE) that is a better match to the other materials used in construction of other SOFC components.
- CTE coefficient of thermal expansion
- SOFC seal members have similar CTE to other components of the SOFC stack in order to minimize mechanical stresses that would otherwise lead to cell cracking and delamination during thermal cycling.
- seal locations within a SOFC stack where it is advantageous to use a chemically invulnerable seal material, even at the cost of a greater CTE mismatch. These include seal locations where contact between the seal and the reducing environment (i.e., fuel flow) is greatest, such as at fuel inlets and outlets, and optionally near the fuel inlet manifold.
- relatively more chemically stable in reducing environment glass or glass ceramic first seal materials are used in locations of a SOFC system where contact with the reducing environment (i.e., fuel flow) is greatest, and CTE-matched glass or glass ceramic second seal materials are used in locations where minimizing mechanical stresses is more important than chemical stability, such as for seal locations with relatively large contact areas between the SOFC components and seal members, as well as any location where the seals are not in contact with the reducing environment.
- chemically stable first seal materials are used in locations such as in areas near the fuel inlet manifold or plenum 11 and/or the fuel inlets and outlets (such as the fuel inlet or outlet riser openings 6 , while CTE-matched second seal members are used in other seal locations that come in contact with the outside ambient or with the air inlet or outlet flows, as shown in FIGS. 1 and 2 .
- the chemically stable first seal materials may comprise the ring seals 5 on the air side of the interconnect and/or a portion of the window seal 10 near the fuel inlet plenum 11 on the fuel side of the interconnect, while the CTE-matched second seal members comprise the strip seals 7 on the air side of the interconnect 1 or the remaining portion of the window seals 10 away from the fuel inlet plenum or manifold 11 .
- each respective seal comprises a single material instead of a combination of a metal seal and a glass or glass ceramic seal materials.
- Examples of materials envisioned for use in preferred chemically stable glass or glass ceramic first seal members include boron oxide (B 2 O 3 )-free glasses or glass ceramics. It is believed that boron negatively effects the seal stability in a reducing environment.
- Examples of materials envisioned for use in preferred CTE-matched glass or glass ceramic second seal members include but are not limited to higher temperature modified borosilicate glasses with a high content of BaO and Al 2 O 3 and lower temperature pure borosilicate glasses.
- the boron oxide containing seals have a desired CTE match to the solid oxide fuel cell stack components.
Abstract
Description
- The present application claims benefit of U.S. provisional application 61/193,596, filed Dec. 9, 2008, which is incorporated herein by reference in its entirety.
- The present invention is generally directed to fuel cell components and more specifically to multiple member protected anode fuel cell seals.
- Fuel cells are electrochemical devices which can convert energy stored in fuels to electrical energy with high efficiencies. High temperature fuel cells include solid oxide and molten carbonate fuel cells. These fuel cells may operate using hydrogen and/or hydrocarbon fuels. There are classes of fuel cells, such as the solid oxide reversible fuel cells, that also allow reversed operation, such that water or other oxidized fuel can be reduced to unoxidized fuel using electrical energy as an input.
- In a high temperature fuel cell system such as a solid oxide fuel cell (SOFC) system, an oxidizing flow is passed through the cathode side of the fuel cell while a reducing flow is passed through the anode side of the fuel cell. The oxidizing flow is typically air, while the reducing flow typically comprises a mixture of a hydrogen-rich gas created by reforming a hydrocarbon fuel source and water vapor. The fuel cell, typically operating at a temperature between 750° C. and 950° C., enables the transport of negatively charged oxygen ions from the cathode flow stream to the anode flow stream, where the ions combine with either free hydrogen or hydrogen in a hydrocarbon molecule to form water vapor and/or with carbon monoxide to form carbon dioxide. The excess electrons from the negatively charged ions are routed back to the cathode side of the fuel cell through an electrical circuit completed between anode and cathode, resulting in an electrical current flow through the circuit.
- Fuel cell stacks are frequently built from a multiplicity of cells in the form of planar elements, tubes, or other geometries. Fuel cell stacks, particularly those with planar geometry, often use seals between electrolyte and interconnect surfaces to contain fuel and air at various locations within the stack. While it is desirable for seals to be effective at start up temperatures to prevent escape (and potential ignition) of fuel gasses, these seals must maintain their operating integrity at high operating temperatures and in an oxidizing, reducing, or mixed (i.e., oxidizing on one side on one side of the seal and reducing on the other) environment. Expansion and contraction of fuel cell stack components (including seals) due to thermal cycling or compression should not result in damage to any of the components during a seal's expected life.
- Many types of seals used at elevated temperatures, such as brazes and metal gaskets, often have a limited life, tolerating only a relatively few number of thermal cycles before they fail to maintain a hermetic seal due to differences in the coefficients of thermal expansion (CTE) that result in mechanical stresses that can lead to failure of the seal or the components of the assembly. Some assemblies are difficult to seal with brazes or gaskets because of operating conditions or material incompatibilities. Also, brazes and metal gaskets often present difficulties and high costs of fabrication and assembly due to the tighter tolerances which are required, in flatness for example, to ensure formation of a hermetic seal.
- Many compliant seals, such as elastomeric o-rings and gaskets, form hermetic seals at start up temperatures, do not crack and tend to absorb stresses in an assembly that arise from thermal expansion and compression. However, these seals cannot be used in high temperature conditions because the elastomeric materials used in them decompose, degrade, or oxidize at high temperatures.
- An embodiment of a first aspect of the present invention provides a method of sealing a fuel cell stack comprising forming a seal with a metal seal member and one or more additional seal members; wherein said metal seal member is exposed to a reducing environment in the interior of the fuel cell system.
- An embodiment of the second aspect of the invention includes a method of operating a fuel cell stack, said method comprising providing fuel into a fuel cell stack, providing air into a fuel cell stack, allowing fuel to permeate through a secondary seal from at least one fuel channel in a first interconnect into a chamber located in the fuel cell stack between a primary and the secondary seals, and allowing air to flow into the chamber from an air channel in a second interconnect through an opening in the electrolyte to form a protective environment in the chamber for the primary seal.
- An embodiment of the third aspect of the invention includes fuel cell stack comprising a plurality of fuel cells, a plurality of interconnects, one or more first seal members comprising a first seal material which are located within the fuel cell stack in fuel flow areas, and one or more second seal members comprising a second seal material different from the first seal material which are located within the fuel cell stack in air flow areas. The one or more first seal members are more chemically stable in a reducing environment than the one or more second seal members, and the one or more second seal members are better coefficient of thermal expansion (CTE) matched to the fuel cells and interconnects than the one or more first seal members.
-
FIG. 1A is a top view of an exemplary interconnect from a SOFC with a multiple member donut barrier seal. -
FIG. 1B is a close up view of an exemplary multiple member donut bather seal. -
FIG. 2 is a three dimensional view of an exemplary interconnect from a SOFC with a multiple member window barrier seal. -
FIG. 3 is a top view of a exemplary donut seal where a gap is defined between two seal members. -
FIG. 4 is a top view of a second exemplary donut seal where two seal members abut. -
FIG. 5 is a side cross sectional view of repeating elements in an exemplary SOFC stack employing a multiple member seal of the third and fourth aspects of the present invention. - Unless otherwise noted, as used herein, the term “forming an effective seal” does not require the formation of a perfectly hermetic seal. Rather, forming an effective seal indicates that a seal member is defining the boundary of a pressure differential or is forming a physical deterrent to substantial gas flow from one side of the seal to the other. As used herein, a “semipermeable seal” is an effective seal in that it allows it allows some transfer of gas flow from one side of the seal to the other while maintaining a physical deterrent to substantial gas flow across the seal. Conversely, a “hermetic seal” is a seal that prevents substantially all gas movement across the boundary defined by the seal. Such seals may be referred to herein as impermeable seals.
- As used herein, the terms “inside” or “inner” describe the position of one seal member relative to another in a multiple member seal where the inside or inner seal member is at a position closer to the interior of the sealed area. Conversely, the outer or outside member is at a position closer to the outside of the sealed area.
- As used herein, the term “typical SOFC operating temperature” includes a temperature that falls within the range of 750° C. to 950° C., inclusive.
- As used herein, a seal member's thickness is the distance between two elements in contact with the seal member. In the case of a SOFC, the two elements may be two planar stack elements that form a top and bottom of the seal member.
- As used herein, a seal member's width is the distance from the inside of the sealed area to the outside of the sealed area.
- As used herein, a seal in a “mixed environment” has a reducing environment on one side of the seal and an oxidizing environment on the other. In a SOFC, the reducing environment is the fuel/water mixture within the fuel cell system and the oxidizing environment is either the outside of the fuel cell system or a portion of the oxidizing flow within the fuel cell system.
- Certain glass and glass ceramic compounds have been shown to be able to provide robust high temperature seals and have coefficients of thermal expansion (CTE) that are well matched with the those of electrolytes and interconnects used in typical SOFCs. This CTE matching is important to minimize mechanical stresses that would otherwise lead to cell cracking and delamination during thermal cycling. However, well CTE-matched glass and glass ceramic seals typically have a shortcoming in that their effectiveness diminishes with prolonged operation in a high temperature reducing environment, such as the fuel/water mixture in a SOFC. It is therefore desirable to have a method of sealing a fuel cell system with a CTE-matched glass or glass ceramic high temperature seal, yet reducing contact of chemically vulnerable glass or glass ceramic seals and the high temperature reducing environment of the SOFC.
- The inventors realized that a plurality of seal members with dissimilar compositions, performance characteristics, and chemical vulnerabilities to reducing environments can be utilized together to form fuel cell seals that are effective at containing high temperature reducing environments within a SOFC system. Seal materials useful in the present invention that are not chemically vulnerable to reducing environments at typical SOFC operating temperatures need not be able to form and maintain hermetic seals at these temperatures. Conversely, seal materials useful in the present invention that are capable of forming and maintaining hermetic seals at typical SOFC operating temperatures need not be chemically invulnerable to reducing environments at the same temperatures.
- Seals useful in all aspects of the present invention can be constructed in any geometric shape necessary for their application. For example, a SOFC stack may contain multiple fuel cells, manifolds for fuel and/or air, and various internal interconnects. At the junction of each of these components, a distinctively shaped seal may be required to maintain an effective seal at typical operating temperatures. Exemplary geometric shapes include rings (i.e., donuts), strips (both shown in
FIG. 1 ), or rectangles (i.e., windows) (shown inFIG. 2 ) or any combination thereof. Multiple member seals of the present invention will be particularly useful at any junction where the seal is presenting a barrier to the reducing environment, i.e. the fuel/water flow, such as hydrogen or hydrocarbon fuel (including methane, natural gas, etc.) and water vapor, of the fuel cell system. Other seal shapes may be used for other configurations. -
FIG. 1A shows the air side of anexemplary interconnect 1. The interconnect may be used in a stack which is internally manifolded for fuel and externally manifolded for air. The interconnect containsair flow grooves 2 to allow air to flow from oneside 3 to the opposite side 4 of the interconnect. Ring seals 5 are located around fuelmanifold riser openings 6. Strip seals (not shown) are located on lateral sides of theinterconnect 1. -
FIG. 1B shows a close up view of anexemplary seal 5.Seals 5 and lateral strip seals contain ametal seal member 8 which faces the fuel/water flow areas and a glass or glassceramic seal member 9 which faces the air flow areas. Thus, inseals 5,member 8 is the inner seal member andmember 9 is the outer seal member. In lateral seals of air sides of interconnects,member 8 would be the outer seal member andmember 9 would be the inner seal member. -
FIG. 2 illustrates the fuel side of theinterconnect 1. Awindow seal 10 is located on the periphery of theinterconnect 1.Seal 10 contains themetal seal member 8 as the inner seal member and the glass or glassceramic seal member 9 as the outer seal member. Also shown arefuel distribution plenums 11 andfuel flow grooves 12. It is important to note that the interconnect shown inFIG. 2 has two types offuel flow grooves 12; however, this is not a limitation of the present invention. The fuel side of an interconnect may havefuel flow grooves 12 that are all the same depth and length, or a combination of short and long, and/or deep and shallow grooves. The air side of theinterconnect 1 contacts a cathode of one cell in the stack while the fuel side ofinterconnect 1 contacts an anode of the adjacent cell. - Multiple member seals of the first aspect of the present invention comprise a metal seal member and one or more additional seal members. In embodiments of this aspect, a metal seal member of a multiple member seal is positioned to lie between a more chemically vulnerable seal member, such as a glass or glass ceramic seal member, and a reducing environment (such as a fuel/water flow) within a fuel cell. A metal seal member may be processed into any suitable form; for example foil, wire, or felt. Preferably, the metal used for a metal seal member comprises gold, silver, nickel, tin, or any alloy thereof.
- In preferred embodiments, at least one of the one or more additional seal members comprise glass or glass ceramic. Glass or glass ceramic seal members can be processed in any suitable process, such as dispensing, tape casting and tape punching. Such processes are numerous and well known in the art. Examples of materials for glass or glass ceramic second seal members include higher temperature modified borosilicate glasses with a high content of BaO and Al2O3 and lower temperature pure borosilicate glasses, although any other glass or glass ceramic material with a suitable viscosity profile can be used.
- The metal seal member facing a fuel/water flow forms a protective barrier against fuel/water exposure for the second glass or glass ceramic seal member. Formation of a perfect hermetic seal by the metal first seal member is not necessary to provide a protective barrier; merely forming an effective seal is sufficient to keep the bulk of the reducing environment from contacting the more vulnerable glass or glass ceramic seal member. However, the closer the seal formed by the metal seal member is to being hermetic, the more effective the protective barrier will be, thus allowing for a longer effective lifespan of the glass or glass ceramic seal member.
- Irrespective of the geometric shape adopted by embodiments of the first or second aspects of the invention, any two seal members can be positioned such that they are in contact (i.e., abut) or positioned such that a gap is defined between them.
- An illustration of an exemplary concentric ring seal where a gap is defined between two seal members is found in
FIG. 3 . As seen in this figure, agap 13 is located between anouter seal member 9 and aninner seal member 8. - An illustration of an exemplary concentric ring seal with abutting seal members is found in
FIG. 4 . As seen in this figure, contact atposition 14 occurs between anouter seal member 9 and aninner seal member 8. - Multiple member seals useful in the second aspect of the present invention comprise one or more secondary seal members comprising a material that is chemically stable in a mixed environment (i.e., reducing flow, such as a fuel/water flow, on one side of the seal member and oxidizing flow, such as air, on the other) and one or more primary seal members. Further, a gap is defined between the secondary seal member and the primary seal member such that at least one channel is defined through which a protective oxidizing flow is flowed. In this type of seal, the one or more secondary seal members are located in the fuel cell stack such that the fuel/water is on one side of the seal member and the one or more secondary seal members need only form an effective, but not hermetic, seal. Materials useful in constructing primary and secondary seal members may be processed in any suitable process, such as dispensing, tape casting and tape punching. Such processes are numerous and well known in the art.
- Embodiments of seals according to the second aspect of the present invention utilize one or more primary seal members to effectively isolate areas of the fuel cell stack from either the outside atmosphere or areas of air flow within the fuel cell stack and one or more secondary seal members prevent reducing flow inside of the fuel cell system from contacting and degrading the primary seal members. Preferably, at least one of the one or more primary seal members comprises a glass or glass ceramic seal member. The secondary seal members comprise a material capable of forming merely an effective seal at typical SOFC operating temperatures. The material of the second seal members also must be relatively chemically invulnerable to the reducing atmosphere. For example, a secondary seal member may comprise a metal or metallic felt. Preferably, the metal or metallic felt used for a secondary seal member will comprise gold, silver, nickel, tin, or any alloy thereof.
- Examples of materials envisioned for use in preferred glass or glass ceramic primary seal members include higher temperature modified borosilicate glasses with a high content of BaO and Al2O3 and lower temperature pure borosilicate glasses, although any other glass or glass ceramic material with a suitable viscosity profile can be used.
- In embodiments of these aspects, SOFC components are adapted to allow for an oxidizing flow to enter a channel defined between the outermost secondary seal member and the innermost primary seal member at a pressure lower than the pressure of the reducing flow. As indicated above, in these embodiments the secondary seal members need not form a hermetic seal; a small amount of leakage of the reducing environment into the channel between the seal members is acceptable. Due to the differences in the pressures of the reducing flow and oxidizing flows found on either side of the secondary seal, any leakage across the seal will be in the form of the reducing flow entering the oxidizing flow in the channel. Thus, the oxidizing flow in the channel will act as a protective buffer in that any reducing environment that escapes containment will contact the protective oxidizing flow in the channel and be neutralized before it can contact the outermost primary seal member. For this reason, the one or more primary seal members need not be chemically invulnerable to a reducing atmosphere. The primary seal members do, however, need to be able to hermetically form and maintain a seal at typical SOFC operating temperatures. Preferably, the one or more primary seal members hermetically seal the fuel cell system at these temperatures.
- SOFC components can be adapted in a number of ways to allow for the low pressure oxidizing gas flow to flow through the chamber described above. In preferred embodiments, the SOFC system is a planar stack system utilizing planar electrolytes and interconnects. In these embodiments, the planar electrolytes (for electrolyte supported cells) have small vent holes or perforations in electrolyte and optionally in electrodes that allow a portion of the oxidizing flow to enter the channels described above. For electrode supported cells, the holes may be formed in the electrodes.
-
FIG. 5 shows a portion of an exemplary SOFC stack including repeatingplanar interconnects 1 andfuel cells 20 utilizing seals according to the second aspect of the present invention. Eachfuel cell 20 includes anelectrolyte 21,anode electrode 22, andcathode electrode 23. This illustration is not meant to be limiting because, as stated above, embodiments of seals useful in the present invention may be fabricated in any geometric shape necessary to contain the reducing flow. Respective air and fuel flow grooves andchannels interconnect 1 are defined between eachrespective electrode fuel flow grooves 12, and the oxidizing flow (e.g., air) is passed in theair flow grooves 2. - Air flows from grooves or
channels 2 intochamber 25 which is bounded on opposite sides by the primary 32 and secondary 31 seals. The air flowing intochamber 25 flows from either air channels in the lower interconnect throughopening 24 in the electrolyte or from air channels above and below the upper interconnect throughopening 34 in the upper andlower interconnects 1.Opening 34 in the interconnect is indicated inFIG. 5 by dashed lines. Note that any combination ofopenings 24 andopenings 34 may be utilized in various embodiments of the present invention to provide air flow tochambers 25 in a fuel cell stack. For example, in some embodiments, only opening 24 in the electrolyte is present. In other embodiments, onlyopenings 34 in the interconnects are present. In still other embodiments, bothopenings grooves 12 through semi-permeablesecondary seal 31 intochamber 25. Air and fuel form a protective environment inchamber 25 that protectsprimary seal 31. - In the third aspect of the present invention, at least two compositionally distinct glass or glass ceramic seal members are used to reduce the contact of the reducing environment in an SOFC system and more chemically vulnerable glass or glass ceramic seal members. The first type of seal member is preferentially composed of a glass or glass ceramic that is more chemically stable in a reducing environment than the second type of seal member. The second type of seal member is preferentially composed of a glass or glass ceramic that has a coefficient of thermal expansion (CTE) that is a better match to the other materials used in construction of other SOFC components.
- As discussed above, it is generally desired that SOFC seal members have similar CTE to other components of the SOFC stack in order to minimize mechanical stresses that would otherwise lead to cell cracking and delamination during thermal cycling. However, there are certain seal locations within a SOFC stack where it is advantageous to use a chemically invulnerable seal material, even at the cost of a greater CTE mismatch. These include seal locations where contact between the seal and the reducing environment (i.e., fuel flow) is greatest, such as at fuel inlets and outlets, and optionally near the fuel inlet manifold.
- Thus, in embodiments of this aspect, relatively more chemically stable in reducing environment glass or glass ceramic first seal materials (i.e., fuel tolerant materials) are used in locations of a SOFC system where contact with the reducing environment (i.e., fuel flow) is greatest, and CTE-matched glass or glass ceramic second seal materials are used in locations where minimizing mechanical stresses is more important than chemical stability, such as for seal locations with relatively large contact areas between the SOFC components and seal members, as well as any location where the seals are not in contact with the reducing environment. In preferred embodiments, chemically stable first seal materials are used in locations such as in areas near the fuel inlet manifold or
plenum 11 and/or the fuel inlets and outlets (such as the fuel inlet oroutlet riser openings 6, while CTE-matched second seal members are used in other seal locations that come in contact with the outside ambient or with the air inlet or outlet flows, as shown inFIGS. 1 and 2 . In other words, the chemically stable first seal materials may comprise the ring seals 5 on the air side of the interconnect and/or a portion of thewindow seal 10 near thefuel inlet plenum 11 on the fuel side of the interconnect, while the CTE-matched second seal members comprise the strip seals 7 on the air side of theinterconnect 1 or the remaining portion of the window seals 10 away from the fuel inlet plenum ormanifold 11. However, in the present embodiment, each respective seal comprises a single material instead of a combination of a metal seal and a glass or glass ceramic seal materials. - Examples of materials envisioned for use in preferred chemically stable glass or glass ceramic first seal members include boron oxide (B2O3)-free glasses or glass ceramics. It is believed that boron negatively effects the seal stability in a reducing environment.
- Examples of materials envisioned for use in preferred CTE-matched glass or glass ceramic second seal members include but are not limited to higher temperature modified borosilicate glasses with a high content of BaO and Al2O3 and lower temperature pure borosilicate glasses. The boron oxide containing seals have a desired CTE match to the solid oxide fuel cell stack components.
- The foregoing description of the invention has been presented for purposes of illustration and description. The methods and devices illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including,” containing”, etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the invention embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/591,986 US8623569B2 (en) | 2008-12-09 | 2009-12-07 | Fuel cell seals |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US19359608P | 2008-12-09 | 2008-12-09 | |
US12/591,986 US8623569B2 (en) | 2008-12-09 | 2009-12-07 | Fuel cell seals |
Publications (2)
Publication Number | Publication Date |
---|---|
US20100159344A1 true US20100159344A1 (en) | 2010-06-24 |
US8623569B2 US8623569B2 (en) | 2014-01-07 |
Family
ID=42266619
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/591,986 Active 2032-02-17 US8623569B2 (en) | 2008-12-09 | 2009-12-07 | Fuel cell seals |
Country Status (1)
Country | Link |
---|---|
US (1) | US8623569B2 (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130071769A1 (en) * | 2010-06-15 | 2013-03-21 | Nissan Motor Co., Ltd. | Fuel cell |
US20130101915A1 (en) * | 2010-06-25 | 2013-04-25 | Utc Power Corporation | Composite seal for fuel cells, process of manufacture, and fuel cell stack using same |
WO2013074746A1 (en) * | 2011-11-17 | 2013-05-23 | Bloom Energy Corporation | Multi-layered coating providing corrosion resistance to zirconia based electrolytes |
US20140127603A1 (en) * | 2012-11-06 | 2014-05-08 | Bloom Energy Corporation | Interconnect and end plate design for fuel cell stack |
CN103843180A (en) * | 2011-09-30 | 2014-06-04 | Toto株式会社 | Solid oxide fuel cell device |
CN103931023A (en) * | 2011-06-15 | 2014-07-16 | Lg燃料电池系统有限公司 | Fuel cell system with interconnect |
US8968509B2 (en) | 2013-05-09 | 2015-03-03 | Bloom Energy Corporation | Methods and devices for printing seals for fuel cell stacks |
US9468736B2 (en) | 2013-11-27 | 2016-10-18 | Bloom Energy Corporation | Fuel cell interconnect with reduced voltage degradation over time |
US9583771B2 (en) | 2013-05-16 | 2017-02-28 | Bloom Energy Coporation | Corrosion resistant barrier layer for a solid oxide fuel cell stack and method of making thereof |
US9923211B2 (en) | 2014-04-24 | 2018-03-20 | Bloom Energy Corporation | Fuel cell interconnect with reduced voltage degradation over time |
US9993874B2 (en) | 2014-02-25 | 2018-06-12 | Bloom Energy Corporation | Composition and processing of metallic interconnects for SOFC stacks |
US10763533B1 (en) | 2017-03-30 | 2020-09-01 | Bloom Energy Corporation | Solid oxide fuel cell interconnect having a magnesium containing corrosion barrier layer and method of making thereof |
CN115000449A (en) * | 2022-06-24 | 2022-09-02 | 西安石油大学 | Method for preparing SOFC (solid oxide Fuel cell) galvanic pile sealing coating by spraying-casting process |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10283804B2 (en) | 2016-10-21 | 2019-05-07 | General Electric Company | Flange assembly for use with a solid oxide fuel cell system |
WO2018203285A1 (en) | 2017-05-04 | 2018-11-08 | Versa Power Systems Ltd | Compact high temperature electrochemical cell stack architecture |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6492053B1 (en) * | 1997-06-10 | 2002-12-10 | Ceramic Fuel Cells Limited | Planar fuel cell assembly |
US20030215689A1 (en) * | 2002-05-16 | 2003-11-20 | Keegan Kevin R. | Solid oxide fuel cell with a metal foam seal |
US20030224238A1 (en) * | 2002-02-20 | 2003-12-04 | Ion America Corporation | High-temperature compliant compression seal |
US20060096632A1 (en) * | 2001-11-05 | 2006-05-11 | Oswald Robert S | Sealed thin film photovoltaic modules |
US20080131739A1 (en) * | 2006-12-05 | 2008-06-05 | Michael Edward Badding | Solutions for solid oxide fuel cell seal failures |
US20090286664A1 (en) * | 2008-05-15 | 2009-11-19 | Melinda Ann Drake | Non-contaminating, electro-chemically stable glass frit sealing materials and seals and devices using such sealing materials |
Family Cites Families (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1809878A1 (en) | 1968-11-20 | 1970-06-11 | Bbc Brown Boveri & Cie | Battery with fuel cells made from a solid electrolyte |
US5589285A (en) | 1993-09-09 | 1996-12-31 | Technology Management, Inc. | Electrochemical apparatus and process |
US5948221A (en) | 1994-08-08 | 1999-09-07 | Ztek Corporation | Pressurized, integrated electrochemical converter energy system |
DE59807606D1 (en) | 1997-06-10 | 2003-04-30 | Goldschmidt Ag Th | Foamable metal body |
JP3456378B2 (en) | 1997-08-21 | 2003-10-14 | 株式会社村田製作所 | Solid oxide fuel cell |
US6302402B1 (en) | 1999-07-07 | 2001-10-16 | Air Products And Chemicals, Inc. | Compliant high temperature seals for dissimilar materials |
US6280869B1 (en) | 1999-07-29 | 2001-08-28 | Nexant, Inc. | Fuel cell stack system and operating method |
US6430966B1 (en) | 1999-07-30 | 2002-08-13 | Battelle Memorial Institute | Glass-ceramic material and method of making |
US6605316B1 (en) | 1999-07-31 | 2003-08-12 | The Regents Of The University Of California | Structures and fabrication techniques for solid state electrochemical devices |
AU8739701A (en) | 2000-08-18 | 2002-03-04 | Global Thermoelectric Inc | High temperature gas seals |
EP1344267A2 (en) | 2000-11-08 | 2003-09-17 | Global Thermoelectric Inc. | Fuel cell interconnect |
US6692859B2 (en) | 2001-05-09 | 2004-02-17 | Delphi Technologies, Inc. | Fuel and air supply base manifold for modular solid oxide fuel cells |
US6635375B1 (en) | 2001-05-29 | 2003-10-21 | The United States Of America As Represented By The United States Department Of Energy | Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation |
US6740441B2 (en) | 2001-12-18 | 2004-05-25 | The Regents Of The University Of California | Metal current collect protected by oxide film |
US7222406B2 (en) | 2002-04-26 | 2007-05-29 | Battelle Memorial Institute | Methods for making a multi-layer seal for electrochemical devices |
EP1525638A2 (en) | 2002-05-09 | 2005-04-27 | Honda Giken Kogyo Kabushiki Kaisha | Fuel cell assembly, separator-diffusion layer assembly for fuel cell assembly and manufacturing method therefor |
WO2004004052A2 (en) | 2002-07-01 | 2004-01-08 | The Regents Of The University Of California | Mems-based fuel cells with integrated catalytic fuel processor and method thereof |
US7947407B2 (en) | 2005-04-27 | 2011-05-24 | Lilliputian Systems, Inc. | Fuel cell apparatus having a small package size |
US20070003821A1 (en) | 2005-06-30 | 2007-01-04 | Freudenberg-Nok General Partnership | Integrally molded gasket for a fuel cell assembly |
CN101313426B (en) | 2005-08-09 | 2012-12-12 | 波利普拉斯电池有限公司 | Compliant seal structures for protected active metal anodes |
US7569299B2 (en) | 2006-07-25 | 2009-08-04 | Gm Global Technology Operations, Inc. | Multi-component fuel cell gasket for low temperature sealing and minimal membrane contamination |
-
2009
- 2009-12-07 US US12/591,986 patent/US8623569B2/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6492053B1 (en) * | 1997-06-10 | 2002-12-10 | Ceramic Fuel Cells Limited | Planar fuel cell assembly |
US20060096632A1 (en) * | 2001-11-05 | 2006-05-11 | Oswald Robert S | Sealed thin film photovoltaic modules |
US20030224238A1 (en) * | 2002-02-20 | 2003-12-04 | Ion America Corporation | High-temperature compliant compression seal |
US20030215689A1 (en) * | 2002-05-16 | 2003-11-20 | Keegan Kevin R. | Solid oxide fuel cell with a metal foam seal |
US20080131739A1 (en) * | 2006-12-05 | 2008-06-05 | Michael Edward Badding | Solutions for solid oxide fuel cell seal failures |
US20090286664A1 (en) * | 2008-05-15 | 2009-11-19 | Melinda Ann Drake | Non-contaminating, electro-chemically stable glass frit sealing materials and seals and devices using such sealing materials |
Cited By (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130071769A1 (en) * | 2010-06-15 | 2013-03-21 | Nissan Motor Co., Ltd. | Fuel cell |
US8999597B2 (en) * | 2010-06-15 | 2015-04-07 | Nissan Motor Co., Ltd. | Fuel cell |
US20130101915A1 (en) * | 2010-06-25 | 2013-04-25 | Utc Power Corporation | Composite seal for fuel cells, process of manufacture, and fuel cell stack using same |
US10050285B2 (en) | 2011-06-15 | 2018-08-14 | Lg Fuel Cell Systems Inc. | Fuel cell system with interconnect |
US10044048B2 (en) | 2011-06-15 | 2018-08-07 | Lg Fuel Cell Systems Inc. | Fuel cell system with interconnect |
CN103931023A (en) * | 2011-06-15 | 2014-07-16 | Lg燃料电池系统有限公司 | Fuel cell system with interconnect |
US9252435B2 (en) | 2011-09-30 | 2016-02-02 | Toto Ltd. | Solid oxide fuel cell device |
CN103843180A (en) * | 2011-09-30 | 2014-06-04 | Toto株式会社 | Solid oxide fuel cell device |
EP2763222A4 (en) * | 2011-09-30 | 2015-06-10 | Toto Ltd | Solid oxide fuel cell device |
US20130130146A1 (en) * | 2011-11-17 | 2013-05-23 | Bloom Energy Corporation | Multi-Layered Coating Providing Corrosion Resistance to Zirconia Based Electrolytes |
JP2015502014A (en) * | 2011-11-17 | 2015-01-19 | ブルーム エネルギー コーポレイション | Multi-layer coating that provides corrosion resistance to zirconia electrolytes |
US20140377680A1 (en) * | 2011-11-17 | 2014-12-25 | Bloom Energy Corporation | Multi-layered coating providing corrosion resistance to zirconia based electrolytes |
US8852825B2 (en) * | 2011-11-17 | 2014-10-07 | Bloom Energy Corporation | Multi-layered coating providing corrosion resistance to zirconia based electrolytes |
US10784521B2 (en) * | 2011-11-17 | 2020-09-22 | Bloom Energy Corporation | Multi-layered coating providing corrosion resistance to zirconia based electrolytes |
WO2013074746A1 (en) * | 2011-11-17 | 2013-05-23 | Bloom Energy Corporation | Multi-layered coating providing corrosion resistance to zirconia based electrolytes |
US9368809B2 (en) * | 2012-11-06 | 2016-06-14 | Bloom Energy Corporation | Interconnect and end plate design for fuel cell stack |
US9368810B2 (en) | 2012-11-06 | 2016-06-14 | Bloom Energy Corporation | Interconnect and end plate design for fuel cell stack |
US20140127603A1 (en) * | 2012-11-06 | 2014-05-08 | Bloom Energy Corporation | Interconnect and end plate design for fuel cell stack |
US9673457B2 (en) | 2012-11-06 | 2017-06-06 | Bloom Energy Corporation | Interconnect and end plate design for fuel cell stack |
US8968509B2 (en) | 2013-05-09 | 2015-03-03 | Bloom Energy Corporation | Methods and devices for printing seals for fuel cell stacks |
US9853298B2 (en) | 2013-05-16 | 2017-12-26 | Bloom Energy Corporation | Corrosion resistant barrier layer for a solid oxide fuel cell stack and method of making thereof |
US10511031B2 (en) | 2013-05-16 | 2019-12-17 | Bloom Energy Corporation | Corrosion resistant barrier layer for a solid oxide fuel cell stack and method of making thereof |
US9583771B2 (en) | 2013-05-16 | 2017-02-28 | Bloom Energy Coporation | Corrosion resistant barrier layer for a solid oxide fuel cell stack and method of making thereof |
US9468736B2 (en) | 2013-11-27 | 2016-10-18 | Bloom Energy Corporation | Fuel cell interconnect with reduced voltage degradation over time |
US9993874B2 (en) | 2014-02-25 | 2018-06-12 | Bloom Energy Corporation | Composition and processing of metallic interconnects for SOFC stacks |
US9923211B2 (en) | 2014-04-24 | 2018-03-20 | Bloom Energy Corporation | Fuel cell interconnect with reduced voltage degradation over time |
US10553879B2 (en) | 2014-04-24 | 2020-02-04 | Bloom Energy Corporation | Fuel cell interconnect with metal or metal oxide contact layer |
US10763533B1 (en) | 2017-03-30 | 2020-09-01 | Bloom Energy Corporation | Solid oxide fuel cell interconnect having a magnesium containing corrosion barrier layer and method of making thereof |
CN115000449A (en) * | 2022-06-24 | 2022-09-02 | 西安石油大学 | Method for preparing SOFC (solid oxide Fuel cell) galvanic pile sealing coating by spraying-casting process |
Also Published As
Publication number | Publication date |
---|---|
US8623569B2 (en) | 2014-01-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8623569B2 (en) | Fuel cell seals | |
US7931997B2 (en) | Multi-material high temperature fuel cell seals | |
US7422819B2 (en) | Ceramic coatings for insulating modular fuel cell cassettes in a solid-oxide fuel cell stack | |
US5942348A (en) | Fuel cell with ceramic-coated bipolar plates and a process for producing the fuel cell | |
JP2012038701A (en) | Fuel cell structure | |
KR20040104657A (en) | Electrochemical cell stack assembly | |
US10164286B2 (en) | Separator-fitted single fuel cell inducing joint portion with protruding portion and sealing portion, and fuel cell stack | |
CN102365780A (en) | Compression arrangement for fuel or electrolysis cells in a fuel cell stack or an electrolysis cell stack | |
EP2472658A1 (en) | A solid oxide fuel cell having a glass composite seal | |
KR20090015121A (en) | Plate solid oxide fuel cell | |
KR20210018421A (en) | Solid Oxide Fuel Cell Stack with Reduced Leakage Unit Cells | |
JP4883733B1 (en) | Fuel cell structure | |
JP2002015751A (en) | Fuel cell and its separator | |
US6709782B2 (en) | Fuel cell having an anode protected from high oxygen ion concentration | |
JP4900364B2 (en) | Fuel cell | |
ES2643601T3 (en) | Three-layer electrically insulating sealing gasket for an SOC unit | |
JP6118230B2 (en) | Fuel cell stack | |
TW202327157A (en) | Fuel cell column including stress mitigation structures | |
KR102144191B1 (en) | Fuel cell stack unit with easy replacement and manufacturing method of the same | |
JP2006344434A (en) | Fuel cell | |
US20080076003A1 (en) | Structure of gasket for preventing contamination of fuel cell stack | |
JP5985160B2 (en) | Fuel cell structure | |
EP3664202B1 (en) | Cell unit | |
CN109478660B (en) | Fuel cell | |
JP4696470B2 (en) | Fuel cell |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BLOOM ENERGY CORPORATION,CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GOTTMANN, MATTHIAS;COUSE, STEPHEN;ARMSTRONG, TAD;AND OTHERS;SIGNING DATES FROM 20091110 TO 20091118;REEL/FRAME:023652/0987 Owner name: BLOOM ENERGY CORPORATION, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GOTTMANN, MATTHIAS;COUSE, STEPHEN;ARMSTRONG, TAD;AND OTHERS;SIGNING DATES FROM 20091110 TO 20091118;REEL/FRAME:023652/0987 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT, CALIFORNIA Free format text: SECURITY INTEREST;ASSIGNOR:BLOOM ENERGY CORPORATION;REEL/FRAME:037301/0093 Effective date: 20151215 Owner name: U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGEN Free format text: SECURITY INTEREST;ASSIGNOR:BLOOM ENERGY CORPORATION;REEL/FRAME:037301/0093 Effective date: 20151215 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: BLOOM ENERGY CORPORATION, CALIFORNIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT;REEL/FRAME:047686/0121 Effective date: 20181126 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 8 |